TZA1025T Philips Semiconductors, TZA1025T Datasheet - Page 8

• Manufacturer Part Number: TZA1025T
• Description: Data amplifier and laser supply circuit for CD audio and video optical systems ADALASLC
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Notes
1. Closed-loop output impedance (10 k feedback resistor connected between pins RFEQO and RFFB).
2. G
3. Values to be used in equation (1).
4. An RF filter of 1 k and 47 pF should be used on the RF output.
5. V
6. An external resistor can be used to reduce the maximum output current (and the gain) of the laser supply;
7. The output impedance strongly depends on the drop voltage (V
8.
9. When a voltage dip at V
1998 Oct 30
V
I
t
RS
V
Control inputs
Z
Z
V
V
i(mon)
sw(on)(LASER)
SYMBOL
i(pd)
i(pu)
i(mon)
clamp
IL
IH
Data amplifier and laser supply circuit for CD
audio and video optical systems (ADALASLC)
ref
see equation (4).
when the drop voltage doubles.
To protect the laser against such peak currents a protection circuit will switch-off the laser current when V
becomes lower than V
RS
drop
RF
ref
= (G
= V
=
DD(L)
RFEQO
-----------------
----------------- -
-------------- -
V
V
monitor input voltage
monitor input current
laser switch-on time
reference supply
rejection
ALPC clamp voltage
pull-down input
impedance pin CDRW
pull-up input
impedance
pin PWRON
LOW-level input
voltage
HIGH-level input
voltage
V
V
mon
DD
mon
DD
N-substrate
P-substrate
pin CDRW
pin PWRON
pin CDRW
pin PWRON
PARAMETER
at f
V
o(LASER)
EQ
)
clamp
DD(L)
(G
.
. When V
RFEQO
occurs it could cause peak currents on I
at 720 kHz).
drop
note 8
note 9
> V
CONDITIONS
clamp
the laser will switch-on automatically again.
8
0.132
V
2
2
200
0.2
0.2
3
3
drop
DD
V
V
DD
DD
MIN.
). The output impedance will approximately double
0.168
o(LASER)
0.150
V
3
200
200
DD
coming out of the ALPC output.
TYP.
0.150
0.168
V
+200
5
0.5
1
1
V
V
3
3
DD
DD
DD
V
V
Product specification
DD
DD
MAX.
+ 0.2
+ 0.2
0.132
TZA1025
drop
V
V
nA
ms
%
V
k
k
V
V
V
V
UNIT